JP2009073862A - Epoxy resin composition for sealing and semiconductor device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an epoxy resin composition for sealing, which is excellent in low thermal expansibility and moldability, has high heat conductivity, and gives packages excellent in low thermal expansibility, heat resistance and moisture resistance when compounded with an inorganic filler. <P>SOLUTION: This epoxy resin composition for sealing, comprising (A) an epoxy resin, (B) a curing agent, and (C) an inorganic filler, is characterized by using an epoxy resin having a diphenyl ether structure represented by general formula (1) [wherein, (n) is the number of ≥0; (m) is an integer of 1 to 3] in an amount of ≥50 wt.% in the epoxy resin component as an epoxy resin component, containing the inorganic filler in an amount of 80 to 95 mass% in the whole composition, and containing a spherical inorganic filler in amount of ≥50 wt.% in the inorganic filler component. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an epoxy resin composition for sealing a semiconductor device, and also relates to a semiconductor device using the same.

  Conventionally, as a sealing method for electrical and electronic parts such as diodes, transistors, and integrated circuits, and semiconductor devices, for example, a sealing method using an epoxy resin or a silicon resin, or a hermetic sealing method using glass, metal, ceramic, or the like In recent years, resin sealing by transfer molding, which can be mass-produced with improved reliability and cost-effective, has been the mainstream in recent years.

  In the resin composition used for the resin sealing method by the transfer molding, a sealing material made of an epoxy resin and a resin composition mainly containing a phenol resin as a curing agent is generally used.

  Currently, an epoxy resin composition used for the purpose of protecting an element such as a power device is filled with an inorganic filler such as crystalline silica at a high density in order to cope with a large amount of heat released from the element.

  Furthermore, in recent years, power devices include one-chip devices incorporating IC technology and those made modular, and further improvements in heat dissipation and thermal expansion properties for sealing materials are desired. ing.

  In order to meet these demands, attempts have been made to use crystalline silica, silicon nitride, aluminum nitride, and spherical alumina powder to improve thermal conductivity (Patent Documents 1 and 2). Increasing the content causes a problem that the fluidity decreases as the viscosity increases during molding, and the moldability is impaired. Therefore, there is a limit to the method of simply increasing the content of the inorganic filler.

  From the above background, there is a demand for higher thermal conductivity of the matrix resin itself. For example, Patent Document 3 and Patent Document 4 propose a resin composition using a liquid crystalline resin having a rigid mesogenic group. Yes. However, the epoxy resin having these mesogenic groups is a substantially single epoxy compound having a rigid structure such as a biphenyl structure and an azomethine structure and having a high crystallinity and a high melting point molecular weight distribution. There was a defect inferior in workability. Furthermore, in order to efficiently orient the molecules in the cured state, it is necessary to cure by applying a strong magnetic field, and there are significant restrictions on facilities for wide industrial use. On the other hand, the thermal conductivity of the inorganic filler is overwhelmingly larger than that of the matrix resin, and even if the thermal conductivity of the matrix resin itself is increased, the actual problem is that the thermal conductivity of the composite material can There was a problem that did not contribute greatly.

  In Patent Document 5, a load applied to a connection electrode portion of a semiconductor device on which a semiconductor element is mounted by a flip chip method or the like is efficiently dispersed and reduced in a sealing resin layer, and severe environmental conditions such as a temperature cycle are reduced. Although the epoxy resin composition for ensuring the electrical conductivity of the semiconductor device is disclosed below, only bisphenol type epoxy resin or the like is disclosed as the epoxy resin. Patent Document 6 discloses an epoxy resin composition for semiconductor encapsulation using a bisphenol-type epoxy resin, but no study of a curing agent has been made, and the purpose is to improve low moisture absorption and heat resistance. And Patent Document 7 discloses a high thermal conductive epoxy resin composition containing spherical cristobalite that gives a cured product having good fluidity, little mold wear, and high thermal conductivity. The means to do is to improve the filler, not to improve the resin. Patent Document 8 discloses an epoxy resin composition that is highly filled with an inorganic filler and can obtain a molded article having excellent thermal conductivity. However, the means for achieving this is improvement of the filler. There is no attempt to improve the resin. Further, in Patent Document 9 relating to the inventors' invention, the behavior of thermal conductivity in a system in which an inorganic filler is blended is not clarified.

JP-A-11-147936 JP 2002-309067 A JP-A-11-323162 JP-A-2004-331811 JP 2001-207031 A Japanese Patent Publication No. 6-51778 JP 2001-172472 A JP 2001-348488 A WO2006 / 120993

  Therefore, the object of the present invention is to solve the above problems, have excellent moldability, high thermal conductivity when combined with an inorganic filler, low thermal expansion, and excellent heat resistance and moisture resistance. The epoxy resin composition for sealing which provides is provided, and also the semiconductor device using the same is provided.

（但し、ｎは０以上の数、ｍは１〜３の整数を示す。）で表されるジフェニルエーテル構造を持つエポキシ樹脂をエポキシ樹脂成分中５０ｗｔ％以上用い、無機充填材の含有率が全組成物中８０〜９５質量％であり、かつ無機充填材成分中、球状無機充填材が５０ｗｔ％以上であることを特徴とする封止用エポキシ樹脂組成物である。すなわち、樹脂層と球状無機充填材の界面における熱抵抗が小さくなるためと推察されるが、本エポキシ樹脂と球状無機充填材を組み合わせた場合において、複合材料としての熱伝導率が特異的に向上することを見出し、本発明に到達したものである。 In order to solve the above problems, an epoxy resin composition for sealing of the present invention is an epoxy resin composition for sealing consisting of an epoxy resin, a curing agent, and an inorganic filler. Formula (1),

(However, n is a number of 0 or more, and m is an integer of 1 to 3.) An epoxy resin having a diphenyl ether structure represented by 50 wt% or more in the epoxy resin component is used, and the content of the inorganic filler is the total composition. It is an epoxy resin composition for sealing, characterized in that it is 80 to 95% by mass in the product and the spherical inorganic filler is 50 wt% or more in the inorganic filler component. In other words, it is assumed that the thermal resistance at the interface between the resin layer and the spherical inorganic filler is reduced, but when this epoxy resin and the spherical inorganic filler are combined, the thermal conductivity as a composite material is specifically improved. The present invention has been found.

  Furthermore, this invention is a semiconductor device obtained using said epoxy resin composition for sealing.

  The present invention will be further described.

（但し、ｍは１〜３の整数を示す。）で表されるビスフェノール化合物とエピクロルヒドリンを反応させることにより製造することができる。この反応は、通常のエポキシ化反応と同様に行うことができる。 The epoxy resin represented by the general formula (1) is represented by the following general formula (3),

(However, m shows the integer of 1-3.) It can manufacture by making the bisphenol compound represented by epichlorohydrin react. This reaction can be performed in the same manner as a normal epoxidation reaction.

  For example, after the bisphenol compound of the general formula (3) is dissolved in excess epichlorohydrin, it is 50 to 150 ° C., preferably 60 to 100 in the presence of an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide. The method of making it react for 1 to 10 hours in the range of ° C is mentioned. In this case, the amount of the alkali metal hydroxide used is in the range of 0.8 to 1.2 mol, preferably 0.9 to 1.0 mol, relative to 1 mol of the hydroxyl group in the bisphenol compound. The epichlorohydrin is used in an excess amount relative to the hydroxyl group in the bisphenol compound, and is usually 1.5 to 15 mol with respect to 1 mol of the hydroxyl group in the bisphenol compound. After completion of the reaction, excess epichlorohydrin is distilled off, the residue is dissolved in a solvent such as toluene, methyl isobutyl ketone, filtered, washed with water to remove inorganic salts, and then the target epoxy is removed by distilling off the solvent. A resin can be obtained.

  In the general formula (1), n is a number of 0 or more, but the value of n can be easily adjusted by changing the molar ratio of epichlorohydrin to the bisphenol compound used in the epoxy resin synthesis reaction. Moreover, as an average value of n, the range of 0.01-1.0 is preferable at the point of melting | fusing point and a viscosity. When larger than this, melting | fusing point and a viscosity will become high and a handleability will fall.

  The bisphenol compound used as a raw material for the epoxy resin used in the present invention is represented by the above general formula (3), and m is 1, 2 or 3, preferably 1 or 2. Specific examples include 4,4′-dihydroxydiphenyl ether, 1,4-bis (4-hydroxyphenoxy) benzene, and 4,4′-bis (4-hydroxyphenoxy) diphenyl ether. As a raw material of the epoxy resin, a mixture thereof may be used. Preferably, the content of 4,4′-dihydroxydiphenyl ether is 50 wt% or more.

  The epoxy resin used for this invention contains the epoxy resin represented by General formula (1) 50 wt% or more in all the epoxy resins, Preferably 70 wt% or more is included. The epoxy equivalent of the epoxy resin represented by the general formula (1) is usually in the range of 160 to 500, but the preferable epoxy equivalent varies depending on the structure of the bisphenol compound to be used. From the viewpoint of improving the properties, those having low viscosity are preferred, and those having an epoxy equivalent in the general formula (1) having n = 0 isomer as a main component in the range of 160 to 300 are preferred.

（但し、ｎは０以上の数を示す。） Among the epoxy resins represented by the general formula (1), an epoxy resin represented by the following general formula (2) is preferable.

(However, n represents a number of 0 or more.)

The epoxy resin represented by the general formula (1) is preferably a crystalline resin that is solid at room temperature, and a desirable melting point is 70 ° C. or higher. The melt viscosity at 150 ° C. is preferably 0.005 to 0.1 Pa · s. In the case where two or more types of epoxy resins are used, the melting point and the melt viscosity are preferably satisfied as a mixture.

The purity of the epoxy resin used in the present invention, in particular the amount of hydrolyzable chlorine, is better from the viewpoint of improving the reliability of the applied electronic component. Although it does not specifically limit, Preferably it is 1500 ppm or less, More preferably, it is 700 ppm or less. In addition, the hydrolyzable chlorine as used in the field of this invention means the value measured by the following method. Specifically, 0.5 g of a sample was dissolved in 30 ml of dioxane, 1N-KOH, 10 ml was added, and the mixture was boiled and refluxed for 30 minutes. The mixture was cooled to room temperature, and further 100 ml of 80% acetone water was added, and a potential difference was obtained with 0.002N-AgNO ₃ aqueous solution. This is a value obtained by titration.

  In addition to the epoxy resin represented by the general formula (1) used as an essential component of the present invention, the epoxy resin used in the present invention is combined with a normal epoxy resin having two or more epoxy groups in the molecule. Also good. Examples include bisphenol A, bisphenol F, 3,3 ′, 5,5′-tetramethyl-4,4′-dihydroxydiphenylmethane, 4,4′-dihydroxydiphenylsulfone, 4,4′-dihydroxydiphenyl sulfide, 4,4'-dihydroxydiphenyl ketone, fluorene bisphenol, 4,4'-biphenol, 3,3 ', 5,5'-tetramethyl-4,4'-dihydroxybiphenyl, 2,2'-biphenol, hydroquinone, resorcin Catechol, t-butylcatechol, t-butylhydroquinone, 1,2-dihydroxynaphthalene, 1,3-dihydroxynaphthalene, 1,4-dihydroxynaphthalene, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 1, 7-dihydroxynaphthalene, 1,8-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 2,4-dihydroxynaphthalene 2,5-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 2,8-dihydroxynaphthalene, allylated or polyallylated products of the above-mentioned dihydroxynaphthalene, allylated bisphenol A, allylated bisphenol F, Divalent phenols such as allylated phenol novolak, or phenol novolak, bisphenol A novolak, o-cresol novolak, m-cresol novolak, p-cresol novolak, xylenol novolak, poly-p-hydroxystyrene, tris- (4 -Hydroxyphenyl) methane, 1,1,2,2-tetrakis (4-hydroxyphenyl) ethane, fluoroglycinol, pyrogallol, t-butyl pyrogallol, allylated pyrogallol, polyallylated pyrogallol Trivalent or higher phenols such as 1,2,4-benzenetriol, 2,3,4-trihydroxybenzophenone, phenol aralkyl resin, naphthol aralkyl resin, dicyclopentadiene resin, or halogen such as tetrabromobisphenol A Glycidyl ethers derived from bisphenols. These epoxy resins can be used alone or in combination of two or more.

  The compounding ratio of the epoxy resin represented by the general formula (1) in the epoxy resin composition is 50 wt% or more in the epoxy resin component, but is preferably 70 wt% or more. If it is less than this, the effect of improving the thermal conductivity when cured is small.

  As the curing agent used in the present invention, any of those generally known as epoxy resin curing agents can be used, but preferred curing agents are phenol-based curing agents. Specific examples thereof include bisphenol A and bisphenol. F, 4,4′-dihydroxydiphenylmethane, 4,4′-dihydroxydiphenyl ether, 1,4-bis (4-hydroxyphenoxy) benzene, 1,3-bis (4-hydroxyphenoxy) benzene, 4,4′-dihydroxy Diphenyl sulfide, 4,4'-dihydroxydiphenyl ketone, 4,4'-dihydroxydiphenyl sulfone, 4,4'-dihydroxybiphenyl, 2,2'-dihydroxybiphenyl, phenol novolak, bisphenol A novolak, o-cresol novolak, m -Cresol novolak, p-cresol novolak, xylenol Borac, poly-p-hydroxystyrene, hydroquinone, resorcin, catechol, t-butylcatechol, t-butylhydroquinone, fluoroglycinol, pyrogallol, t-butyl pyrogallol, allylated pyrogallol, polyallylated pyrogallol, 1,2,4- Benzenetriol, 2,3,4-trihydroxybenzophenone, 1,2-dihydroxynaphthalene, 1,3-dihydroxynaphthalene, 1,4-dihydroxynaphthalene, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 1, 7-dihydroxynaphthalene, 1,8-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 2,4-dihydroxynaphthalene, 2,5-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 2,8 -Dihydroxynaphthalene, above Allylated or polyallyl compound of hydroxynaphthalene, allylated bisphenol A, allylated bisphenol F, allylated phenol novolak, allylated pyrogallol, and the like.

  The curing agent component used in the present invention may be used by mixing two or more kinds of curing agents, but a particularly preferable one is a bifunctional phenol compound as the curing agent component, more preferably 50 wt% or more in the curing agent component. Contains 70 wt% or more. Examples of the bifunctional phenol compound in this case include 4,4′-dihydroxybiphenyl, 4,4′-dihydroxydiphenyl ether, 1,4-bis (4-hydroxyphenoxy) benzene, 4,4′-dihydroxydiphenylmethane, Selected from 4'-dihydroxydiphenyl sulfide, 1,5-naphthalenediol, 2,7-naphthalenediol, 2,6-naphthalenediol, hydroquinone, and resorcinol. Among these, 4,4′-dihydroxybiphenyl, 4,4′-dihydroxydiphenyl ether, and 4,4′-dihydroxydiphenylmethane are particularly preferable.

  As the curing agent of the present invention, in addition to the above-mentioned phenolic curing agent, a curing agent generally known as a curing agent can be used in combination. Examples include amine curing agents, acid anhydride curing agents, phenolic curing agents, polymercaptan curing agents, polyaminoamide curing agents, isocyanate curing agents, block isocyanate curing agents, and the like. What is necessary is just to set the compounding quantity of these hardening | curing agents suitably considering the kind of hardening | curing agent to mix | blend, and the physical property of the heat conductive epoxy resin molded object obtained.

  Specific examples of the amine curing agent include aliphatic amines, polyether polyamines, alicyclic amines, aromatic amines and the like. Aliphatic amines include ethylenediamine, 1,3-diaminopropane, 1,4-diaminopropane, hexamethylenediamine, 2,5-dimethylhexamethylenediamine, trimethylhexamethylenediamine, diethylenetriamine, iminobispropylamine, bis ( Hexamethylene) triamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, N-hydroxyethylethylenediamine, tetra (hydroxyethyl) ethylenediamine and the like. Examples of polyether polyamines include triethylene glycol diamine, tetraethylene glycol diamine, diethylene glycol bis (propylamine), polyoxypropylene diamine, and polyoxypropylene triamines. Cycloaliphatic amines include isophorone diamine, metacene diamine, N-aminoethylpiperazine, bis (4-amino-3-methyldicyclohexyl) methane, bis (aminomethyl) cyclohexane, 3,9-bis (3-amino). Propyl) 2,4,8,10-tetraoxaspiro (5,5) undecane, norbornenediamine and the like. Aromatic amines include tetrachloro-p-xylenediamine, m-xylenediamine, p-xylenediamine, m-phenylenediamine, o-phenylenediamine, p-phenylenediamine, 2,4-diaminoanisole, 2, 4-toluenediamine, 2,4-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 4,4'-diamino-1,2-diphenylethane, 2,4-diaminodiphenylsulfone, 4,4'-diaminodiphenylsulfone , M-aminophenol, m-aminobenzylamine, benzyldimethylamine, 2-dimethylaminomethyl) phenol, triethanolamine, methylbenzylamine, α- (m-aminophenyl) ethylamine, α- (p-aminophenyl) Ethylamine, diaminodiethyldimethyldiphenylmethane, α, α'-bi (4-aminophenyl) -p-diisopropylbenzene and the like.

  Specific examples of acid anhydride-based curing agents include dodecenyl succinic anhydride, polyadipic acid anhydride, polyazeline acid anhydride, polysebacic acid anhydride, poly (ethyloctadecanedioic acid) anhydride, poly (phenylhexadecanedioic acid) Anhydride, Methyltetrahydrophthalic anhydride, Methylhexahydrophthalic anhydride, Hexahydrophthalic anhydride, Methylhymic anhydride, Tetrahydrophthalic anhydride, Trialkyltetrahydrophthalic anhydride, Methylcyclohexenedicarboxylic anhydride, Methylcyclohexenetetracarboxylic Acid anhydride, phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic anhydride, ethylene glycol bis trimellitate, het acid anhydride, nadic anhydride, methyl nadic anhydride, 5- (2,5 -Dioxote (Trahydro-3-furanyl) -3-methyl-3-cyclohexane-1,2-dicarboxylic anhydride, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinic dianhydride, Examples include 1-methyl-dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinic dianhydride.

  In the epoxy resin composition of the present invention, the mixing ratio of the epoxy resin and the curing agent is preferably in the range of 0.8 to 1.5 in terms of an equivalent ratio of the epoxy group and the functional group in the curing agent. Outside this range, unreacted epoxy groups or functional groups in the curing agent remain even after curing, which is not preferable because the reliability with respect to the sealing function is lowered.

  The amount of the spherical inorganic filler used in the present invention is 80 to 95% by mass, preferably 83 to 93% by mass, based on the epoxy resin composition. If it is less than this, the effects of the present invention such as high thermal conductivity and low thermal expansion cannot be achieved, and if it is more than this, the viscosity becomes high and the moldability deteriorates, which is not preferable.

  The spherical inorganic filler used in the present invention is not particularly limited as long as it has a spherical shape including those having a cross section on an ellipse, but from the viewpoint of improving fluidity, it is as close to a true sphere as possible. Is preferred. Thereby, it is easy to take a close-packed structure such as a face-centered cubic structure or a hexagonal close-packed structure, and a sufficient filling amount can be obtained. In the case of a non-spherical shape, when the filling amount is increased, friction between the fillers is increased, and before reaching the above upper limit, the fluidity is extremely lowered to increase the viscosity and the moldability is deteriorated.

  Of the spherical inorganic fillers used, those having a thermal conductivity of 5 W / m · K or more are preferably 50 wt% or more, and alumina, aluminum nitride, crystalline silica, and the like are suitably used. Of these, spherical alumina is particularly preferable. In addition, an amorphous inorganic filler such as fused silica or crystalline silica may be used in combination, if necessary, regardless of the shape.

  The average particle size of the spherical inorganic filler used in the present invention is preferably 30 μm or less. If the average particle size is larger than this, the fluidity of the epoxy resin composition is impaired, and the strength is also lowered, which is not preferable.

  A conventionally well-known hardening accelerator can be used for the epoxy resin composition of this invention. Examples include amines, imidazoles, organic phosphines, Lewis acids, etc., specifically 1,8-diazabicyclo (5,4,0) undecene-7, triethylenediamine, benzyldimethylamine, Tertiary amines such as ethanolamine, dimethylaminoethanol, tris (dimethylaminomethyl) phenol, imidazoles such as 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-heptadecylimidazole, Organic phosphines such as tributylphosphine, methyldiphenylphosphine, triphenylphosphine, diphenylphosphine, phenylphosphine, tetraphenylphosphonium / tetraphenylborate, tetraphenylphosphonium / ethyltriphenylborate, tetra Tetra-substituted phosphonium tetra-substituted borate such as Chiruhosuhoniumu-tetrabutyl borate, 2-ethyl-4-methylimidazole · tetraphenyl port rate, and the like tetraphenyl boron salts such as N- methylmorpholine-tetraphenyl port rate. As addition amount, it is the range of 0.2-10 weight part normally with respect to 100 weight part of epoxy resins. These may be used alone or in combination.

  The addition amount of the curing catalyst is preferably 0.1 to 10.0% by mass with respect to the total of the epoxy resin (including the halogen-containing epoxy resin as a flame retardant) and the curing agent. If it is less than 0.1% by mass, the gelation time is delayed, resulting in a decrease in workability due to a decrease in rigidity at the time of curing. Conversely, if it exceeds 10.0% by mass, curing proceeds during molding and unfilling occurs. It becomes easy to do.

  In the epoxy resin composition of the present invention, a wax can be used as a release agent generally used for an epoxy resin composition for sealing. As the wax, for example, stearic acid, montanic acid, montanic acid ester, phosphoric acid ester and the like can be used.

  In the epoxy resin composition of this invention, in order to improve the adhesive force of an inorganic filler and a resin component, the coupling agent generally used for the epoxy resin composition for sealing can be used. As the coupling agent, for example, epoxy silane can be used. As for the addition amount of a coupling agent, 0.1-2.0 mass% is preferable with respect to the epoxy resin composition for sealing. If it is less than 0.1% by mass, the compatibility between the resin and the base material is poor, and the moldability deteriorates. Conversely, if it exceeds 2.0% by mass, the molded product is soiled by continuous moldability.

  In addition, thermoplastic oligomers can be added to the epoxy resin composition of the present invention from the viewpoint of improving fluidity during molding and improving adhesion to a lead frame and the like. Thermoplastic oligomers include C5 and C9 petroleum resins, styrene resins, indene resins, indene / styrene copolymer resins, indene / styrene / phenol copolymer resins, indene / coumarone copolymer resins, indene / benzothiophene. Examples thereof include copolymer resins. As addition amount, it is the range of 2-30 weight part normally with respect to 100 weight part of epoxy resins.

  Furthermore, what can generally be used for the epoxy resin composition for sealing can be suitably mix | blended and used for the epoxy resin composition of this invention. For example, phosphorus-based flame retardants, flame retardants such as bromine compounds and antimony trioxide, and colorants such as carbon black and organic dyes can be used.

  The epoxy resin composition of the present invention is prepared by uniformly mixing an epoxy resin, a curing agent, an inorganic filler, and other components other than the coupling agent with a mixer, and then adding a coupling agent, a heating roll, a kneader, etc. Kneaded and manufactured. There is no restriction | limiting in particular in the mixing | blending order of these components. Furthermore, after kneading, the melt-kneaded product can be pulverized to be powdered or tableted.

  The epoxy resin composition of the present invention is particularly used for sealing in semiconductor devices.

  In order to obtain a cured product using the epoxy resin composition of the present invention, for example, methods such as transfer molding, press molding, cast molding, injection molding, and extrusion molding are applied, but from the viewpoint of mass productivity. Transfer molding is preferred.

  The cured product of the epoxy resin composition of the present invention preferably has crystallinity from the viewpoint of high thermal conductivity. The expression of the crystallinity of the cured product can be confirmed by observing the endothermic peak accompanying melting of the crystal as a melting point by scanning differential thermal analysis. The preferred melting point is in the range of 150 ° C to 300 ° C, more preferably in the range of 170 ° C to 250 ° C.

  The higher the degree of crystallinity of the cured product of the epoxy resin composition of the present invention, the better. The degree of crystallization can be evaluated from the endothermic amount accompanying the melting of the crystals in the scanning differential thermal analysis. A preferable endothermic amount is 10 J / g or more per unit weight of the resin component excluding the filler. More preferably, it is 15 J / g or more, and particularly preferably 30 J / g or more. If it is smaller than this, the effect of improving the thermal conductivity as a cured epoxy resin is small. Also, higher crystallinity is preferable from the viewpoint of low thermal expansion and improved heat resistance. In addition, the endothermic amount here refers to the endothermic amount obtained by measuring with a differential thermal analyzer under the condition of a heating rate of 10 ° C./min under a nitrogen stream using a sample that is precisely weighed about 10 mg.

  The higher the thermal conductivity of the cured product of the epoxy resin composition of the present invention, the better, and preferably 3 W / m · K or more.

  The cured product of the epoxy resin composition of the present invention can be obtained by heating and curing by the above molding method. Usually, the molding temperature is 80 ° C. to 250 ° C., but the crystallinity of the cured epoxy resin product is In order to increase the temperature, it is desirable to cure at a temperature lower than the melting point of the cured product. A preferred curing temperature is in the range of 100 ° C to 200 ° C, more preferably 130 ° C to 180 ° C. The preferred curing time is 30 seconds to 1 hour, more preferably 1 minute to 30 minutes. Further, after molding, the crystallinity can be further increased by post-cure. Usually, the post-cure temperature is 130 ° C. to 250 ° C., and the time is in the range of 1 hour to 20 hours, but preferably 1 hour at a temperature 5 ° C. to 40 ° C. lower than the endothermic peak temperature in differential thermal analysis. It is desirable to perform post-cure over 24 hours from the beginning.

  The epoxy resin composition of the present invention gives a cured product with excellent moldability and reliability, and excellent thermal conductivity, and is suitably applied as a sealing material for semiconductor elements, etc., and has excellent high heat dissipation and dimensional stability. Sex is demonstrated.

  Hereinafter, the present invention will be described more specifically with reference to examples.

Reference example 1
202 g of 4,4′-dihydroxydiphenyl ether was dissolved in 1400 g of epichlorohydrin, and 161.6 g of 48% aqueous sodium hydroxide solution was added dropwise under reduced pressure (about 120 mmHg, 60 ° C. over 4 hours. During this time, the water produced was epichlorohydrin and The distilled epichlorohydrin was returned to the system, and the reaction was continued for another hour, after which the salt formed by filtration was removed, and after washing with water, the epichlorohydrin was distilled off. As a result, 302 g of a pale yellowish white crude epoxy resin was obtained, the epoxy equivalent was 171 and the hydrolyzable chlorine was 4200 ppm, and the obtained epoxy resin was dissolved in 6000 ml of methyl isobutyl ketone to obtain 20% sodium hydroxide. 15.0 g of an aqueous solution was added and reacted at 80 ° C. for 2 hours. Then, after filtration and washing with water, methyl isobutyl ketone as a solvent was distilled off under reduced pressure to obtain 278 g of a pale yellowish white epoxy resin (epoxy resin A). The decomposable chlorine was 280 ppm, the melting point was 78 to 84 ° C., and the viscosity at 150 ° C. was 6.2 mPa · s In addition, the ratio of each component in the general formula (1) determined by GPC measurement of the obtained resin N = 0 was 91.5% and n = 1 was 8.5%.

Here, hydrolyzable chlorine is obtained by dissolving 0.5 g of a sample in 30 ml of dioxane, adding 1 N-KOH, 10 ml, boiling and refluxing for 30 minutes, cooling to room temperature, and further adding 100 ml of 80% acetone water. Is a value measured by performing potentiometric titration with a 0.002N-AgNO ₃ aqueous solution. The melting point is a value obtained by a capillary method at a heating rate of 2 ° C./min. Viscosity was measured with a product manufactured by BROOKFIELD, CAP2000H, and softening point was measured by a ring and ball method according to JIS K-6911. In addition, GPC measurement was carried out using a device: Nippon Waters Co., Ltd., Model 515A, column: TSK-GEL2000 × 3 and TSK-GEL4000 × 1 (both manufactured by Tosoh Corp.), solvent: tetrahydrofuran, flow rate: 1 ml / min, temperature; 38 ° C., detector; RI conditions were followed.

Reference example 2
The reaction was conducted in the same manner as in Reference Example 1 using 150 g of 4,4′-dihydroxydiphenyl ether, 50 g of 1,4-bis (4-hydroxyphenoxy) benzene and 1400 g of epichlorohydrin, and 284 g of a pale yellowish white epoxy resin was obtained. Obtained (epoxy resin B). The epoxy equivalent of the obtained epoxy resin was 171, hydrolyzable chlorine was 240 ppm, and the viscosity at 150 ° C. was 9.2 mPa · s.

Reference example 3
Epoxy resin composition obtained by melt-mixing 9.3 g of epoxy resin A obtained in Reference Example 1, 5.7 g of 4,4′-dihydroxydiphenyl ether as a curing agent, and 0.15 g of triphenylphosphine as a curing accelerator at 120 ° C. It was a thing. Then, it heat-cured at 150 degreeC for 1 hour, and was set as the molded product. The obtained molded product was further post-cured at 175 ° C. for 12 hours, a test piece was prepared, and the thermal conductivity was measured. The thermal conductivity of the cured epoxy resin was 0.30 W / m · K.

Reference example 4
Preparation of the composition in the same manner as in Reference Example 3, using 9.9 g of a biphenyl-based epoxy resin (manufactured by Japan Epoxy Resin, YX-4000H; epoxy equivalent 195) and 5.1 g of 4,4′-dihydroxydiphenyl ether as a curing agent, Molding was performed to prepare a test piece, and the thermal conductivity was measured. The thermal conductivity of the cured epoxy resin was 0.26 W / m · K.

Reference Example 5
Phenol novolac type epoxy resin (manufactured by Toto Kasei, YDPF-638; epoxy equivalent 164, melt viscosity 0.06 Pa · s at 150 ° C.) 9.9 g, phenol novolak (manufactured by Gunei Chemical Co., PSM-4261; OH) as a curing agent (Equivalent 103, softening point 82 ° C, melt viscosity 0.16 Pa · s at 150 ° C) 5.1 g, the composition was adjusted and molded in the same manner as in Reference Example 3, and a test piece was prepared to conduct heat. The rate was measured. The thermal conductivity of the cured epoxy resin was 0.21 W / m · K.

Examples 1-6, Comparative Examples 1-3
As an epoxy resin component, the epoxy resins of Reference Examples 1 and 2 (epoxy resins A and B), biphenyl epoxy resin (epoxy resin C: manufactured by Japan Epoxy Resin, YX-4000H; epoxy equivalent 195), phenol novolac epoxy resin ( Epoxy resin D: manufactured by Toto Kasei Co., Ltd., YDPF-638; epoxy equivalent 164, melt viscosity at 150 ° C. of 0.06 Pa · s), o-cresol novolac type epoxy resin (epoxy resin E: manufactured by Nippon Kayaku Co., Ltd., EOCN-1020) Epoxy equivalent 199, softening point 54 ° C., melt viscosity 0.09 Pa · s at 150 ° C.), 4,4′-dihydroxydiphenyl ether (curing agent A), 4,4′-dihydroxybiphenyl (curing agent B) as curing agent 2,6-dihydroxynaphthalene (curing agent C), phenol novolak (hard Agent D: manufactured by Gunei Chemical Co., Ltd., PSM-4261; OH equivalent 103, softening point 82 ° C., melt viscosity at 150 ° C. 0.16 Pa · s), curing accelerator triphenylphosphine, inorganic filler as spherical alumina ( Inorganic filler A: average particle size 12.2 μm, thermal conductivity 25 W / m · K), spherical fused silica (inorganic filler B: average particle size 14.8 μm, thermal conductivity 1.3 W / m · K) The ingredients shown in Table 1 were mixed, mixed thoroughly with a mixer, then kneaded with a heating roll for about 5 minutes, cooled and crushed, and sealed in Examples 1 to 5 and Comparative Examples 1 and 2, respectively. An epoxy resin composition was obtained. The epoxy resin composition was cured and post-cured under the conditions shown in Table 1, and the physical properties of the cured product were evaluated in the same manner as in Example 1. The results are summarized in Table 1. In addition, the number of each compound in Table 1 represents parts by weight.

[Evaluation]
(1) Thermal conductivity Thermal conductivity was measured by the unsteady hot wire method using an LFA447 type thermal conductivity meter manufactured by NETZSCH.
(2) Measurement of melting point and heat of fusion (DSC method)
Using a differential scanning calorimeter (Seiko Instruments DSC6200 type), the temperature was increased at a rate of 10 ° C./min. In addition, since the hardened | cured material of Comparative Examples 1-3 does not crystallize, melting | fusing point does not exist.
(3) Linear expansion coefficient and glass transition temperature The linear expansion coefficient and glass transition temperature were measured at a temperature elevation rate of 10 ° C / min using a TMA120C type thermomechanical measuring device manufactured by Seiko Instruments Inc.
(3) Water absorption rate A disk having a diameter of 50 mm and a thickness of 3 mm was formed, and after post-curing, the weight change rate was obtained after moisture absorption at 85 ° C. and a relative humidity of 85% for 100 hours.

Claims (9)

In the epoxy resin composition for sealing consisting of (A) an epoxy resin, (B) a curing agent, and (C) an inorganic filler, the following general formula (1),

(However, n is a number of 0 or more, and m is an integer of 1 to 3.) An epoxy resin having a diphenyl ether structure represented by 50 wt% or more in the epoxy resin component is used, and the content of the inorganic filler is the total composition. An epoxy resin composition for sealing, characterized in that it is 80 to 95 wt% in the product, and the spherical inorganic filler in the inorganic filler component is 50 wt% or more.   The epoxy resin composition for sealing according to claim 1, wherein the spherical inorganic filler is alumina, aluminum nitride, or crystalline silica. The epoxy resin is represented by the following general formula (2),

The epoxy resin composition for sealing according to claim 1, wherein n is an epoxy resin represented by the formula (1).   The epoxy resin composition for sealing according to any one of claims 1 to 3, wherein a bifunctional phenol compound is used as a curing agent component in an amount of 50 wt% or more in the curing agent component.   Bifunctional phenolic compounds are 4,4'-dihydroxybiphenyl, 4,4'-dihydroxydiphenyl ether, 1,4-bis (4-hydroxyphenoxy) benzene, 4,4'-dihydroxydiphenylmethane, 4,4'-dihydroxydiphenyl The epoxy resin composition for sealing according to claim 4, which is selected from the group consisting of sulfide, 1,5-naphthalenediol, 2,7-naphthalenediol, 2,6-naphthalenediol, hydroquinone and resorcin.   Hardened | cured material whose heat conductivity obtained by hardening | curing the epoxy resin composition in any one of Claims 1-5 is 3 W / m * K or more.   Hardened | cured material which has the peak of melting | fusing point in the range of 150 to 300 degreeC in the scanning differential thermal analysis obtained by hardening | curing the epoxy resin composition in any one of Claims 1-5.   The hardened | cured material of Claim 7 whose heat absorption amount of the resin component conversion in the scanning differential thermal analysis obtained by hardening | curing the epoxy resin composition in any one of Claims 1-5 is 10 J / g or more.   A semiconductor device comprising the sealing epoxy resin composition according to claim 1.